The semiconductor industry uses thin wafers in the fabrication of semiconductor devices, thereby leading to the requirement of thinning down a bonded wafer. However, edge of the thinned wafer, known as the non-bond area, is prone to peel or crack and therefore damaging the semiconductor devices in the thinned wafer. Peeling defect from wafer edge is a key factor of production yield, therefore the treatment of wafer edge under wafer bonding scenario becomes more and more important to enhance production yield. For example, wafer edge trimming is one of the most common arts that can remove the non-bond area of the wafer before the bonding and thinning operation.
Yet during the process of wafer edge trimming, a great number of particles generated from the wafer edge would land on the pre-bond surface of the wafer. These particles could induce bonding bubbles, or gate oxide integrity (GOI) fail in silicon on insulator (SOI) development. Conventionally, cleaning process is applied to remove a portion but not all particles on the pre-bond wafer surface. Furthermore, the damaged surface caused by particles cannot be effectively recovered by cleaning process.